COVID-19-related acute kidney injury; incidence, risk factors and outcomes in a large UK cohort

• Published in: BMC Nephrology 2021, Vol.22 (1)
• Main Authors: Jewell, Paul D, Bramham, Kate, Galloway, James, Post, Frank, Norton, Sam, Teo, James, Fisher, Richard, Saha, Rohit, Hutchings, Sam, Hopkins, Phil, Smith, Priscilla, Joslin, Jennifer, Jayawardene, Satish, Mackie, Sarah, Mudhaffer, Ali, Holloway, Amelia, Kibble, Henry, Akter, Mosammat, Zuckerman, Benjamin, Palmer, Kieran, Murphy, Ciara, Iatropoulou, Domniki, Sharpe, Claire C, Lioudaki, Eirini
• Format: Report
• Language: English
• Subjects: Acute renal failure; Patient outcomes; Risk factors; Statistics
• ISSN: 1471-2369; 1471-2369
• DOI: 10.1186/s12882-021-02557-x

Background Acute kidney injury (AKI) is common among patients hospitalised with COVID-19 and associated with worse prognosis. The aim of this study was to investigate the epidemiology, risk factors and outcomes of AKI in patients with COVID-19 in a large UK tertiary centre. Methods We analysed data of consecutive adults admitted with a laboratory-confirmed diagnosis of COVID-19 across two sites of a hospital in London, UK, from 1st January to 13th May 2020. Results Of the 1248 inpatients included, 487 (39%) experienced AKI (51% stage 1, 13% stage 2, and 36% stage 3). The weekly AKI incidence rate gradually increased to peak at week 5 (3.12 cases/100 patient-days), before reducing to its nadir (0.83 cases/100 patient-days) at the end the study period (week 10). Among AKI survivors, 84.0% had recovered renal function to pre-admission levels before discharge and none required on-going renal replacement therapy (RRT). Pre-existing renal impairment [odds ratio (OR) 3.05, 95%CI 2.24-4,18; p < 0.0001], and inpatient diuretic use (OR 1.79, 95%CI 1.27-2.53; p < 0.005) were independently associated with a higher risk for AKI. AKI was a strong predictor of 30-day mortality with an increasing risk across AKI stages [adjusted hazard ratio (HR) 1.59 (95%CI 1.19-2.13) for stage 1; p < 0.005, 2.71(95%CI 1.82-4.05); p < 0.001for stage 2 and 2.99 (95%CI 2.17-4.11); p < 0.001for stage 3]. One third of AKI3 survivors (30.7%), had newly established renal impairment at 3 to 6 months. Conclusions This large UK cohort demonstrated a high AKI incidence and was associated with increased mortality even at stage 1. Inpatient diuretic use was linked to a higher AKI risk. One third of survivors with AKI3 exhibited newly established renal impairment already at 3-6 months. Keywords: COVID-19, AKI, Mortality, Renal replacement therapy